How to Tile a Hearth

By: Harry Sawyers

Shopping List

Supplies You Will Need

1. TILES
Available at home centers and tile dealers, though most high-end tile requires ordering as much as six weeks in advance. Tiles are sold by the square foot, ranging in price from $2 to about $50. You should look for tiles with a foot-traffic rating of 3 or above (on a scale of 1 to 5). Given a set of measurements, some tile dealers will calculate how much you need, and art-tile manufacturers may make you all the tiles, in the right sizes, to order. But you can also determine the square footage yourself: Multiply the length in inches by the width, and divide the result by 144. Then add 10 percent to that number for waste cuts.

2. ½-INCH CEMENT OR FIBER-CEMENT BACKER BOARD
to go over a plywood subfloor and create a flat, stable surface for installation.

3. CONSTRUCTION ADHESIVE
to glue backer board to the subfloor.

4. 11/4-INCH BACKER-BOARD SCREWS
to screw the backer board to the subfloor.

5. UNMIXED THINSET MORTAR
Also known as setting cement. One 50-pound bag should be enough. Do not use mastic; it can’t take high heat.

6. LATEX ADDITIVE
to mix with the thinset, as the liquid. It improves flexibility and creates a stronger bond than a water-based mix.

7. TILE SPACERS
Porcelain tiles can have as little as a 1/8-inch gap between them, while ceramic tiles can be 3/6 to 3/8 inch apart and terra-cotta tiles can be spaced 3/4 inch apart. Handmade tiles may require special surface spacers that accommodate irregularities on the top edge. Buy spacers appropriate for your tile type and the grout lines your layout dictates.

8. GROUT
Use sanded grout if the space between your tiles will be greater than 1/8 inch, unsanded if it’s smaller. You can also buy colored grout to more closely match your tile.

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Tools List
Tools You Will Need
- Utility Knife
- Drill/Driver with mixing paddle
- 3/8-Inch Notched Trowel
- Caulking Gun
- Wet-cutting Tile Saw
  (rents for about $40 a day)
- 4 Foot level
- Putty Knife
- Rubber Grout Float
- Grout Sponge
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Product selections for this project
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Photo: Kolin Smith

7. Grout the joints

Using a grout sponge and/or a putty knife, clean out any joints where the thinset has squeezed out. Once the tiles are set, clean, and evenly spaced, leave the thinset to dry for 24 hours. Remove the spacers.

Following the directions on the packaging, mix the grout with water until it resembles peanut butter. Using a grout float held at at angle, spread a layer of grout diagonally across the joints, pushing the mix between the tiles. Work the float in all directions to ensure all the joints are full; never sweep it parallel to the joints or it will catch in the gaps and pull up the mix. Do not grout the joint around the edge of the hearth.

Once the joints are well packed, turn the float on edge and, again sweeping diagonally across the joints, scrape off the excess grout. Let the grout dry about 30 to 60 minutes, until firm to the touch.

Dampen a grout sponge and squeeze out the excess water. Wipe the surface of the tiles in a circular motion to clean off the excess grout. Once the tiles look fairly clean, leave the grout to dry overnight, until a thin haze covers the tiles. Then, using a clean, dry rag, buff off the haze.

Fill the joint around the perimeter of the hearth with caulk that matches the grout. Smooth the caulk with a wet finger. Allow the hearth to set for another two or three days before building a fire.